There are a number of asphalt based products commercially used especially for roofing materials such as roofing shingles. These roofing materials have a limited life, and although under proper circumstances a new layer of material can be laid over an existing layer, at some point the shingles must be removed and properly disposed of as waste. Typically, the old roofing materials are disposed of in a landfill and therefore present environmental problems.
Although there are known processes for recycling these roofing materials, the composition of them can present environmental concerns and processing complications. For example, attempts have been made to recycle asphalt roofing material through rather expensive and complex processes using a considerable amount of equipment and in which liquid asphalt is added. A number of the known processes produce a liquid product. Richards U.S. Pat. No. 5,367,007 teaches a process which uses recycled asphalt shingles that requires the addition of material to produce a multi-layer paving block containing thermoplastic materials. There is however, not known any simple process in which recycled roofing materials can be used to produce blocks at a cost where they can be commercially used in various applications for paving, walkways, etc.
It is therefore an object of the invention to make a useful product from a normally discarded material such as asphalt roofing material. It is a further object of the invention to produce a unique and simple process that can economically produce asphalt blocks made from recycled materials that can be used on patios, sidewalks, or for paving of driveways and roadways that have low traffic volume.
The invention is for a process and the product produced by the process in which recycled asphalt shingles are reduced into granules in any suitable manner. The granules are then heated to a temperature above 212xc2x0 F. in order to evaporate any water contained in the material. Once substantially all the water has been evaporated, the heated granules are then placed in a suitable mold and compressed under high pressure to form a block of the desired size and shape after which the blocks are removed from the mold.